Background - Minimally invasive surgical
procedures involve the use of surgical instruments and a miniature video camera
(laparoscope) inserted through small incisions in the abdomen. The laparoscope
sends a magnified image from inside the body to a video monitor giving the
surgeon a close-up view of organs and tissues. The surgeon uses this view to
identify various anatomical structures that are manipulated using surgical
instruments. While minimally invasive procedures are effective, the limited
information provided by the laparoscope camera can make it difficult, in some
cases, to differentiate key anatomical features, which may lead to unnecessary
surgical complications.

Approach - The goal of this research was to
demonstrate the feasibility of overlaying imagery from a laparoscopic ultrasound
(LUS) onto laparoscopic imagery to create an augmented view in a test bed
environment. Ultimately, this approach would be extended to enhance a surgeon's
ability to identify key anatomical features during actual procedures. The
approach taken involved the development of an accurate and usable method for
tracking both the ultrasound and laparoscopic probes using off-the-shelf
components, generating methods for correlating and overlaying imagery from the LUS and laparoscope in a single composited image updated in real time, and
developing a prototype user interface allowing the user to view and interact
with imagery from the laparoscope and LUS.

Accomplishments - We successfully developed a
proof-of-concept system that demonstrated the basic approach. We worked with
surgeons to collect data using the proof-of-concept system to support a study to
determine if combining imagery in this fashion was more effective than depicting
the images separately, as is currently done during laparoscopic surgery using
ultrasound. Study results were generally positive and illustrated that the
approach allowed subjects to answer orientation questions 33 to 50 percent
faster than using the conventional approach. In addition, a post-study survey
showed a favorable opinion of this image overlay technique.